There should be no functional difference, except that the error message
is changd from "three or no arguments" to "zero or three arguments". Somehow
the inverted form always seemed strange.
umask() call is also dropped from run-generator. I think it wasn't dropped in
053254e3cb because the run generator was merged
around the same time.
This is really useful for running commands like this:
# systemd-run -i someimage.raw -b systemd.run='"some command line"'
This will now run the command line inside a small Type=oneshot service
and even propagate the exit code of the command back to the parent. And
all that with the full system booted up.
By default this causes the system to shutdown right after the command
completed, but this can be tweaked with systemd.run_success_action= and
systemd.run_failure_action=.
Note that when used in VMs the exit status can of course not be
propagate, as VMs don't really know a concept for that.
Yu Watanabe